Level crossing structures

ABSTRACT

The invention relates to level crossing structures of the kind in which slabs, which form part of the roadway and on whose upper edge level with the rails there is a stepped recess for a wheel rim, are held in place by a lower part, projecting from the recess and engaging moulded bodies forming a bearing and adapted to conform with the lateral profile of the rails.

United States Patent [191 artl I [451 July 23,1974

[ LEVEL CROSSING STRUCTURES [75] Inventor: Gerhard Hartl, Vienna, Austria [73] Assignee: Semperit Aktiengesellschaft, Vienna,

Austria [22] Filed: July 10, 1972 [21] Appl. No.: 270,025

[30] Foreign Application Priority Data July 9, 1971 Austria 5980/71 [52] US. Cl. 238/8 [51] Int. Cl E01b 21/00 [58] Field of Search 238/8, 283, 7, 6, 9, 2

[56] References Cited UNITED STATES PATENTS 1,649,192 11/1927 Rogers 238/9 2,996,256 8/1961 Moses 238/283 3,317,137 5/1967 Harmon 238/8 3,469,783 9/1969 Uralli et a1 238/8 Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Richard A. Bertsch Attorney, Agent, or Firm--Ernest F. Marmorek The invention relates to level crossing structures of the kind in which slabs, which form part of the roadway and on whose upper edge level with the rails there is a stepped recess for a wheel rim, are held in place by a lower part, projecting from the recess and engaging moulded bodies forming a bearing and adapted to conform with the lateral profile of the rails.

ABSTRACT 2 Claims, 5 Drawing Figures PATENTEDJUL23I974 3,825,184

SHEET 1 BF 4 PRIOR ART. 19 1b BACKGROUND OFTHE INVENTION In US. Pat. No. 3,643,864, there is disclosed a construction in which slabs consisting of concrete, for example, are-arranged both between the rails and outside the latter to form the road surface. These plates have projections, by means of which they are held in place in moulded bodies, e.g. rubber sections,engaging the rails. These rubber sections are adapted on the side facing the rails to conform with the lateral profile of the rails and on the side facing the slabs they have a bearing for the slabs.

However, considerable shortcomings have revealed themselves in the practical use of a level crossing of this kind. As a result of the continuous movement of road vehicles passing over the crossing, vibration effects occur, which cause the dislocation of at least the bottom sectional part of the moulded bodies and usually the formation of cracks in the bearing edge.

SUMMARY OF THE INVENTION The invention consists in a level crossing structure comprising a plurality of slabs which form part of the roadway, on whose upper edge on the side facing the rails there is a stepped recess for a wheel rim and which are held in place by a lower part, projecting from the recess and engaging moulded bodies forming a bearing member and adapted to conform with the lateral profile of the rails wherein an essential feature of the invention is that each slab has on its underside a second stepped recess adapted to interact with the bearing member; and wherein the bearing lies flush, on the side facing the slab, against both the substantially vertical and the substantially horizontal surface of the recess on the underside of the slab. The moulded bodies are preferably made of rubber. Using a structure according to the invention the bearing member is prevented from dislocation even when subject to slab vibration and the formation of cracks in the bearing edge is largely overcome.

Both these effects can be avoided to a still greater extend by additional measures-Thus at least one part of the bearing surface of the bearing member lying against the rail profile and preferably the substantially horizontal part, may be provided with serrations which run, for example, in the direction of the rails.

The bearing member may be further anchored in the stepped recess by virtue of the fact that therecess limited longitudinally by one or more walls, so that the stepped recess becomes a kind of half box. It has been shown that, especially in level crossings where the rails run at an angle other than a right angle to the median plane of the road way, there is the danger'not only of a dislocation of the bearing portion of the bearing member downwards, but also of a lateral displacement. This lateral displacement can be practically completely prevented by this wallformation.

In order to prevent the formation of cracks in the bearing edge, a groove, which may be of semicircular cross-section, may beprovided in the bearing member in thevicinity of'the upper edge of the second stepped recess in the slab, so that by avoiding a sharp edge, there is substantially less stress on the rubber material at this edge. The rubber sections are preferably bevelled at the points of the smallest radius of curvature of the lateral profile of the rails in such a way that they do not come into contact with the latter at these points,

- but form a cavity. Since the rail profile is subject to certain tolerance variations, the presence of plus tolerances would otherwise exert a pressure on the rubber profile at this point, which could be transmitted to the bearing edge and there lead to the formation of cracks.

form additionally to the angle of installation'of the rails,

which often deviates significantly from the perpendicular. With the very large forces exerted by the slabs on the rubber sections when heavyv vehicles pass over, even minor inaccuracies can bring about deformations and, as a consequence, the formation of cracks in the bearing member.

BRIEF DESCRIPTION OF THE DRAWING Exemplary embodiments of the invention will now be described with reference to the drawings forming part of this Specification, in which:

FIGS. la and lb shows known forms of level crossing I in section; v

FIGS. 2 and 3 show two embodiments according to the invention of profiles for a level crossing, in section; and

. FIG. 4 shows a slabfor the crossing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. la, a known level crossing has slabs 1 and 2, which are supported on a rail 6 by moulded bodies 3, 4 and 5, forming a bearing. The moulded bodies 4 and 5 which together correspond to the shape of the moulded body 3 are, however, made separately so as to provide easy assembly of the crossing. This known construction has the disadvantage that, as shown in FIG. 1b as a result of the bearing pressure of the slabs l and 2 the lower sections 8 and 7 of the moulded bodies 3 and 5 respectively are forced away from the rail by the inclination of the base of the rail, the elements being torn I apart at the transition regions 9 andv 10.

According to the invention, the slabs l and 2, as shown in FIG. 2, are provided with stepped recesses l l and'12, in which the'moulded parts 3' and Slie flush.-

So as to avoid as far as possible any slipping ofthe moulded bodies 3 and 5, the bottom surfaces 13 and 7 14 thereof are provided with serrationswhich run in the direction of the rails. However, any other: appropriate surface structure may be. provided instead of the serrations. In order to prevent irregular fitting of the which are most at risk, the moulded bodies 3 and are provided in the region of these sections with a semicircular recess 19, running in the longitudinal direction of the rails.

To achieve a better force distribution, the rails are generally installed at an angle a to the vertical, as shown in FIG. 3. The Figure also shows moulded bodies 3", 4" and 5", which allow for this sloping position of the rail 6 with regard to the slabs 1 and 2. As the slope of the rails is generally constant, the profiles of the moulded bodies can also be the same.

FIG. 4 shows a slab 2, in which the stepped recess 12 is interrupted longitudinally by wall sections 20 and 21. This construction prevents the moulded bodies from being laterally displaced. However, in place of these wall sections, other projections and depressions or special profilings may be provided on the slabs, which prevent the moulded bodies from being pushed out laterally.

What is claimed is:

l. A level crossing structure for a rail system comprising a plurality of slabs which form part of a roadway, the slabs positioned on one side of a rail having at the upper edges thereof on the side facing the rail a stepped upper recess adapted for a wheel rim and which slabs are held in place by a lower part, projecting from said upper recess and engaging molded bodies forming a bearing member, said molded bodies being made of rubber, said bearing member being adapted to conform with the lateral profile of the rail, each of the slabs having on its underside a stepped lower recess, said stepped lower recess being adapted to interact with the bearing member whereby the bearing member lies flush, on the side facing the associated slab, against both the substantially vertical and the substantially horizontal surfaces of said lower recess.

2. A level crossing structure for a rail system comprising a plurality of slabs which form part of a roadway, the slabs positioned on one side of a rail having at the upper edges thereof on the side facing the rail a stepped upper recess adapted for a wheel rim and which slabs are held in place by a lower part, projecting from said upper recess and engaging molded bodies fonning a bearing member, said bearing member being adapted to conform with the lateral profile of the rail, having such configuration that a cavity is defined between the web and flange on one hand and between the web and head on the other hand, each of the slabs having on its underside a stepped lower recess adapted to interact with the bearing member whereby the bearing member lies flush, on the side facing the associated slab, against both the substantially vertical and the substantially horizontal surfaces of said lower recess. 

1. A level crossing structure for a rail system comprising a plurality of slabs which form part of a roadway, the slabs positioned on one side of a rail having at the upper edges thereof on the side facing the rail a stepped upper recess adapted for a wheel rim and which slabs are held in place by a lower part, projecting from said upper recess and engaging molded bodies forming a bearing member, said molded bodies being made of rubber, said bearing member being adapted to conform with the lateral profile of the rail, each of the slabs having on its underside a stepped lower recess, said stepped lower recess being adapted to interact with the bearing member whereby the bearing member lies flush, on the side facing the associated slab, against both the substantially vertical and the substantially horizontal surfaces of said lower recess.
 2. A level crossing structure for a rail system comprising a plurality of slabs which form part of a roadway, the slabs positioned on one side of a rail having at the upper edges thereof on the side facing the rail a stepped upper recess adapted for a wheel rim and which slabs are held in place by a lower part, projecting from said upper recess and engaging molded bodies forming a bearing member, said bearing member being adapted to conform with the lateral profile of the rail, having such configuration that a cavity is defined between the web and flange on one hand and between the web and head on the other hand, each of the slabs having on its underside a stepped lower recess adapted to interact with the bearing member whereby the bearing member lies flush, on the side facing the associated slab, against both the substantially vertical and the substantially horizontal surfaces of said lower recess. 